I am probably repeating some tips, but here is how I would recommend approaching:

Start with your environment. Set up a proper study space that is uncluttered and has enough space to work. Preferably this is a dedicated space that no one else uses/changes. Make sure it is not near distractions like TV, people talking, etc.

Try establishing a routine, and stick to it. Have a good starting time you can maintain. Find the right duration to study - at what point do you start to fidget/lose focus? Figure out if changing subjects, taking a break, or changing the type of activity you are doing (e.g. writing instead of reading) helps you maintain your ability to study. Additionally, you may want to determine a time limit per day.

Experiment with various study techniques, and pay attention to what helps: maybe having a classmate help you get started; maybe dividing work assignments into smaller chunks (and try aligning with your study time chunks); getting help when studying for tests specifically; using a calendar to track due dates for assignments / tests.

You can also experiment with giving yourself incentives - reward yourself when you feel you accomplished tasks/goals.

Don't be afraid to consider a tutor or talking to your teachers for advice.

Finally, try keeping a journal so you can keep track of what worked and what didn't.

Also switching to types notes saves time and is more readible, which gives you time to actually study them! Also focus first on figures and once you understand those you can scan for keywords and other info that seems relavant. (College junior)

KEEP IN MIND
Consider that each fact or theory or concept you read about, learn about, incorporate into your long term memory may be retrieved and possibly become a key piece of data that you might use in any number of ways. You never know what information you've acquired that will prove vital to you down the line.

Does anyone know how they figured out how to fix the 1.5 billion dollar Hubble Space Telescope? When it was initially positioned in orbit its image was distorted. The 94.5" primary mirror was off by less than the thickness of a human hair, 2 microns.

Actually, it was the most precise telescope ever made by human hands. It just had a spherical aberration. Well, the answer occurred to James Crocker, a senior engineer at Ball Aerospace Corp., one morning while standing in a shower during a trip to Germany.

Check it out. We don't have to waste any of our experiences. We can learn and keep learning how to do and improve things, all the time.

If you are a kid with ADHD and you're receiving the help you need to focus your attention, you are the most fortunate of people. To have life ahead of you with your brain functioning, so that you can read and follow lectures and conversations, you have been given a tremendous gift! With our determination, our intuition, our lightening fast brains that are working, with our tenacity, you can realize dreams you've never dreamed.